After a first-place primary finish on Tuesday, former Gov. Mark Sanford remains the front-runner to win South Carolina’s 1st District as he heads to a Republican runoff with attorney Curtis Bostic on April 2.

Bostic is less familiar to the electorate than Sanford, a former congressman from that area. The personal-injury lawyer has a smaller fundraising base, plans to eschew negative advertising during the runoff and is seen by operatives as too focused on his social conservatism in a district where fiscal conservatism is paramount.

“It looks pretty good for Sanford. He drew the ideal opponent,” said Will Folks, an influential political blogger in the state who is neutral in the race.

Sanford took 37 percent in Tuesday’s 16-person GOP primary, while Bostic took 13 percent. Because no candidate received more than 50 percent of the vote, the top two finishers head to a runoff.

There have been instances in South Carolina where the top vote-getter in the primary is upset in the runoff. But insiders see Bostic, a former Charleston County councilman, as an unlikely candidate to pull off that feat.

“More than likely that Sanford will be the nominee,” said Richard Quinn Sr., a longtime South Carolina GOP consultant who is unaligned in the race. “There’s some sentiment that Mr. Bostic is too much the captive of the evangelical, religious right."

One South Carolina Republican operative, also unaligned in the race, saw Bostic’s strong focus on social issues such as abortion as a potential hindrance to victory.

“This is a district that’s more Club for Growth than Focus on the Family,” the operative said, referring, respectively, to an anti-tax group and a Christian group that emphasizes biblical principles in marriage and child-rearing.

Bostic campaign manager David O’Connell pushed back.

“Anybody who meets Curtis Bostic knows he’s a great guy and he appeals to many different stripes of Republican voters — and general-election voters, too,” he said.

But there are other hurdles Bostic has to overcome to win, including introducing himself to voters and raising money.

From Jan. 1 to Feb. 27, Sanford raised $334,000 from individuals, while Bostic raised just $87,000, according to Federal Election Commission reports. During that period, Bostic loaned his campaign $100,000 — and Republicans say he could further fund his campaign if he wants.

Insiders see a strong negative ad campaign as a useful tool to defeat Sanford. As governor, he disappeared from the state for days in 2009 and then admitted to an extramarital affair with a woman from Argentina. He had told staff that he was hiking the Appalachian Trail.

“Sanford is [a] pinata waiting to happen for the right candidate,” said Folks, who is a former Sanford aide. “I just don’t think this is the right candidate.”

Bostic has pledged to stay positive during the primary.

“I don’t anticipate any negativity during the runoff,” O’Connell said.

In advertisements and on the trail, Sanford has emphasized his record, in Congress and in Columbia, as a tried-and-true fiscal conservative. That theme won't change.

O'Connell said Bostic would continue to focus on the district's grass roots. He said the campaign knocked on about 5,000 doors during the primary and that helped Bostic overcome being outspent — by hundreds of thousands of dollars — on the airwaves.

“The task in front of us is no greater than the task we just completed,” O’Connell said.